1 files changed, 150 insertions, 0 deletions
diff --git a/src/htab.c b/src/htab.c
new file mode 100644
index 0000000..dde8430
--- /dev/null
+++ b/src/htab.c
@@ -0,0 +1,150 @@
+/* since hsearch_r does not support deletions dirctly, this is an abstraction on
+ * top of it with support for deletions, for this to work properly we have to
+ * strdup the key, this is not a big issue for 100k drv_path strings, it's
+ * either this or pulling in a external library
+ */
+
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "htab.h"
+#include "util.h"
+
+#define MAX_NIX_PKG_COUNT 200000
+
+static int htab_keys_insert(struct htab *htab, char *key);
+
+static int htab_keys_insert(struct htab *htab, char *key)
+{
+	size_t newsize;
+	void *ret;
+
+	if (htab->key_filled < htab->keys_size) {
+		htab->keys[htab->key_filled++] = key;
+		return 0;
+	}
+
+	newsize = htab->keys_size == 0 ? 1 : htab->keys_size * 2;
+	ret = realloc(htab->keys, newsize * sizeof(*htab->keys));
+	if (ret == NULL) {
+		print_err("%s", strerror(errno));
+		return -errno;
+	}
+
+	htab->keys = ret;
+	htab->keys_size = newsize;
+	htab->keys[htab->key_filled++] = key;
+
+	return 0;
+}
+
+int htab_search(struct htab *htab, char *key, ENTRY **ep)
+{
+	ENTRY e;
+	int ret;
+
+	e.key = key;
+	e.data = NULL;
+	ret = hsearch_r(e, FIND, ep, htab->table);
+	if (ret == 0) {
+		if (errno != ESRCH) {
+			print_err("%s", strerror(errno));
+			return -errno;
+		}
+		return ESRCH;
+	}
+
+	if ((*ep)->data == NULL) {
+		return ESRCH;
+	} else {
+		return 0;
+	}
+}
+
+int htab_enter(struct htab *htab, const char *key, void *data)
+{
+	ENTRY e, *ep;
+	int ret;
+
+	e.key = strdup(key);
+	if (e.key == NULL) {
+		print_err("%s", strerror(errno));
+		return -errno;
+	}
+
+	e.data = data;
+	ret = hsearch_r(e, ENTER, &ep, htab->table);
+	if (ret == 0) {
+		print_err("%s", strerror(errno));
+		return -errno;
+	}
+	ep->data = NULL;
+
+	if (ep->key != e.key) {
+		free(e.key);
+	} else {
+		ret = htab_keys_insert(htab, e.key);
+		if (ret < 0)
+			free(e.key);
+	}
+
+	return ret;
+}
+
+int htab_delete(struct htab *htab, const char *key)
+{
+	return htab_enter(htab, key, NULL);
+}
+
+int htab_init(struct htab **htab)
+{
+	int ret;
+	struct htab *h;
+
+	h = malloc(sizeof(*h));
+	if (h == NULL) {
+		print_err("%s", strerror(errno));
+		return -errno;
+	}
+
+	h->table = calloc(1, sizeof(*h->table));
+	if (h == NULL) {
+		print_err("%s", strerror(errno));
+		ret = -errno;
+		goto out_free_h;
+	}
+
+	ret = hcreate_r(MAX_NIX_PKG_COUNT, h->table);
+	if (ret == 0) {
+		print_err("%s", strerror(errno));
+		ret = -errno;
+		goto out_free_table;
+	}
+	ret = 0;
+
+	h->keys = NULL;
+	h->keys_size = 0;
+	h->key_filled = 0;
+
+out_free_table:
+	if (ret < 0)
+		free(h->table);
+out_free_h:
+	if (ret < 0)
+		free(h);
+	else
+		*htab = h;
+
+	return ret;
+}
+
+void htab_free(struct htab *htab)
+{
+	for (size_t i = 0; i < htab->key_filled; i++)
+		free(htab->keys[i]);
+
+	free(htab->keys);
+	free(htab->table);
+	free(htab);
+}